A MEMS device is known in which minute electrical parts and machine parts are integrated. As such a MEMS device, a micro-relay, a pressure sensor, an acceleration sensor and so on are exemplified. The MEMS device is desired to have a high bonding strength and to be manufactured by using a room-temperature bonding technique which does not need a pressing process due to load and a heating process.
A wafer bonding method is also known in which a plurality of devices are formed on a bonding substrate obtained by bonding two substrates with a plurality of patterns. In the method, it is desired to improve a yield of the plurality of devices and to apply a load on the bonding plane more uniformly.
In Japanese Patent Publication (JP-A-Heisei 09-321097), a pressing apparatus is disclosed in which even when contact surfaces of bumps on a work with the bumps are inclined, all the bumps can be pressed against an electrode of a work with uniform force. The pressing apparatus of the work with bumps includes a pressing body driven by a driving unit to move up and down, and an elastic member attached to the lower surface of the pressing body and pressed to the upper surface of the work with bumps. A concave portion is formed in the lower surface of the pressing body in order to permit that the elastic member is expanded into an upper direction to elastically deform.
In Japanese Patent Publication (JP 2007-301593A), a pressing apparatus is disclosed in which uniform pressure can be applied on a pressure surface of a pressure object. In the pressing apparatus, the pressure is applied to the pressure object by a pressure head. The pressure head has a first space section on a pressure axis of a pressing section.